It is of vital importance, before attempting to operate your engine, to read the general 'SAFETY INSTRUCTIONS AND WARNINGS' section on pages 2-6 of this booklet and to strictly adhere to the advice contained therein.

● Also, please study the entire contents of this instruction manual, so as to familiarize yourself with the controls and other features of the engine.

Keep these instructions in a safe place so that you may readily refer to them whenever necessary.

It is suggested that any instructions supplied with the aircraft, radio control equipment, etc., are accessible for checking at the same time.

●

●

CONTENTS

SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE

INTRODUCTION,BEFORE INSTALLING THE ENGINE

BASIC ENGINE PARTS INSTALLATION OF THE ENGINE

THROTTLE LINKAGE, SILENCER

FUEL TANK LOCATION

GLOWPLUG

FUEL,PROPELLERS

CARBURETOR CONTROLS

STARTING

RUNNING-IN (Breaking-in)

IDLING ADJUSTMENT CHART

MIXTURE CONTROL VALVE ADJUSTMENT

SUBSEQUENT STARTING PROCEDURESUBSEQUENT READJUSTMENT

CARBURETOR CLEANLINESS,ENGINE CARE AND MAINTENANCE

ENGINE EXPLODED VIEWS &ENGINE PARTS LISTS

CARBURETOR EXPLODED VIEWS & PARTS LISTS

ENGINE THREE VIEW DRAWINGS

GENUINE O.S. PARTS & ACCESSORIES

2~6

7

8~9

10

11

11~12

12~13

13~14

14~15

15~17

18

19

20

21

22~23

24

25

26

1

Remember that your engine is not a "toy", but a highly efficient internal-combustion machine whose power is capable of harming you, or others, if it is misused.As owner, you, alone, are responsible for the safe operation of your engine, so act with discretion and care at all times.If at some future date, your O.S. engine is acquired by another person, we would respectfully request that these instructions are also passed on to its new owner.

SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE

The advice which follows is grouped under two headings according to the degree of damage or danger which might arise through misuse or neglect.

WARNINGS NOTES

These cover events which might involve serious (in extreme circumstances, even fatal) injury.

These cover the many other possibilities, generally less obvious sources of danger, but which, under certain circumstances, may also cause damage or injury.

2

WARNINGS

Model engine fuel is poisonous. Do not allow it to come into contact with the eyes or mouth. Always store it in a clearly marked container and out of the reach of children.

Never operate your engine in an en-closed space. Model engines, like auto-mobile engines, exhaust deadly carbon-monoxide. Run your engine only in an open area.

Model engines generate considerable heat. Do not touch any part of your engine until it has cooled. Contact with the muffler (silencer), cylinder head or exhaust header pipe, in particular, may result in a serious burn.

•

•

•

•

Never touch, or allow any object to come into contact with, the rotating propeller and do not crouch over the engine when it is running.

A weakened or loose propeller may disintegrate or be thrown off and, since propeller tip speeds with powerful engines may exceed 600 feet(180 metres) per second, it will be understood that such a failure could result in serious injury, (see 'NOTES' section relating to propeller safety).

•

Model engine fuel is also highly flammable. Keep it away from open flame, excessive heat, sources of sparks, or anything else which might ignite it. Do not smoke or allow anyone else to smoke, near to it.

•

3

NOTES

•

•

•

•

•

This engine was designed for model aircraft. Do not attempt to use it for any other purpose.

Mount the engine in your model securely, following the manufacturers' recommenda-tions, using appropriate screws and lock-nuts.

Be sure to use the silencer (muffler) supplied with the engine. Frequent exposure to an open exhaust may eventually impair your hearing. Such noise is also likely to cause annoyance to others over a wide area.

Install a top-quality propeller of the diameter and pitch specified for the engine and aircraft. Locate the propeller on the shaft so that the curved face of the blades faces forward-i.e. in the direction of flight. Firmly tighten the propeller nut, using the correct size wrench.

If you remove the glowplug from the engine and check its condition by connecting the battery leads to it, do not hold the plug with bare fingers.Use an appropriate tool or a folded piece of cloth.

4

NOTES•

•

Always check the tightness of the propeller nut and retighten it, if necessary, before restarting the engine, particularly in the case of four-stroke-cycle engines. If a safety locknut assembly is provided with your engine, always use it. This will prevent the propeller from flying off in the event of a "backfire", even if it loosens.

If you fit a spinner, make sure that it is a precision made product and that the slots for the propeller blades do not cut into the blade roots and weaken them.

Preferably, use an electric starter. The wearing of safety glasses is also strongly recommended.

•

• Discard any propeller which has become split, cracked, nicked or otherwise rendered unsafe. Never attempt to repair such a propeller: destroy it. Do not modify a propeller in any way, unless you are highly experienced in tuning propellers for specialized competition work such as pylon-racing.

Take care that the glow plug clip or battery leads do not come into contact with the propeller. Also check the linkage to the throttle arm. A disconnected linkage could also foul the propeller.

After starting the engine, carry out any needle-valve readjustments from a safe position behind the rotating propeller. Stop the engine before attempting to make other adjustments to the carburetor.

•

•

5

NOTES•

•

•

•

•

Adjust the throttle linkage so that the engine stops when the throttle stick and trim lever on the transmitter are fully retarded. Alternatively, the engine may be stopped by cutting off the fuel supply. Never try to stop the engine physically.

Take care that loose clothing (ties, shirt sleeves, scarves, etc.)do not come into contact with the propeller.Do not carry loose objects (such as pencils, screwdrivers, etc.) in a shirt pocket from where they could fall through the propeller arc.

Do not start your engine in an area containing loose gravel or sand. The propeller may throw such material in your face and eyes and cause injury.

For their safety, keep all onlookers (especially small children) well back (at least 20 feet or 6 meters) when preparing your model for flight. If you have to carry the model to the take-off point with the engine running, be especially cautious. Keep the propeller pointed away from you and walk well clear of spectators.

Warning! Immediately after a glowplug-ignition engine has been run and is still warm, conditions sometimes exist whereby it is just possible for the engine to abruptly restart if the propeller is casually flipped over compression WITHOUT the glowplug battery being reconnected. Remember this if you wish to avoid the risk of a painfully rapped knuckle!

6

BA

C

This engine is ideally suited to a variety of R/C aircraft,including sports and scale types.

A separate precision-made needle-valve unit is installed at the rear, where manual adjustment is safely remote from the rotating propeller.

An effective low-loss 855 silencer is supplied.

INTRODUCTION

•

•

•

BEFORE INSTALLING THE ENGINEIn addition to the general tools, the following tools are convenient to use.

10mm wrench to secure nuts, preferably 2 pcs.

14-17mm open end wrench

Large capacity electric starter and battery

•

•

•

Carefully insert plug, with washer, fingertight only, before final tightening with the correct size plug wrench.

Installing the glowplug

Glow plugWasher

Installing the remote needleInstall the remote needle to the attachment bracket as shown in the following.

First, make sure that nut A and B are secured using a 10mm wrench. Then, fit the remote needle to the attachment bracket, and tighten nut A and C.

•

•

Remote Needle

Remote Needle Valve Bracket

Connect the needle-valve to carburettor jet nozzle with silicone tubing supplied. In the event of the tubing becoming damaged, it should be replaced with 78mm length of 5mm ODx2mm ID silicone tubing.

7

BASIC ENGINE PARTS

Drive HubPropeller Washer

Propeller Nut

Crankcase

Lock Nut

Crankshaft

Cylinder Head

CarburettorType 7D-RN

Glow plug

Cover Plate

Fuel inlet

Silicone tubing

Remote Needle

Fuel outlet

INSTALLATION OF THE ENGINE

Rigid hardwood(e.g. maple)

At least12mm(1/2")

At least12mm(1/2")

O.S. radial motor mount (Available as an optional extra part. See parts list)

A typical method of beam mounting is shown below, left.

Installation in the model

For 108FSR(BX-1) (Code No. 71907000)

8

Make sure that the mounting beams are parallel and that their top surfaces are in the same plane.

Hardwood mounting beams

O.S. radial motor mount(cast aluminum)

How to fasten the mounting screws.Tighten second nut firmlydown onto first nut.

Tighten this nut first.

Steel washer

5mm steel screw

Spring washer or lock washer

Hardwood such as cherry or maple.

Spring washer

5mm steel Allen screw

5mm steel nuts

Use mounting screws of a diameter (between 5mm) appropriate to engine size (see table left).

Front view Side view

Top surfacesare not in thesame plane.

Oppositebeam

Top surfacesare not in thesame plane.

Re-align the surfaces as necessary

Engine does notrest firmly.

CORRECT

INCORRECT

Top surfaces are in the same plane.

9

M4 ✕ 15

M3.5 ✕ 12

M4 ✕ 18

Before connecting the throttle-lever / servo linkage, make sure that no part of the linkage interferes with the internal structure of the aircraft or wiring, etc., when the throttle is fully open or fully closed.

Set the throttle lever linkage so that the throttle ro-tor is (a) fully open when the transmitter throttle stick is fully advanced and (b) fully closed when the throttle stick is fully retarded. Adjustment of the throttle rotor opening at the idling position can then be made with the throttle trim lever on the transmit-ter. (Select throttle-lever and servo-horn hole posi-tions that will avoid excessive pushrod travel caus-ing the throttle to bind at either end.)

THROTTLE LINKAGE•

•

The exhaust outlet of the silencer can be rotated to any desired position in the following manner:

Loosen the locknut and assembly screw.Set the exhaust outlet at the required position by rotating the rear part of the silencer.Re-tighten the assembly screw, followed by the locknut.

SILENCER

1)2)

3)

Assembly screw

Exhaust outlet

Locknut

Install the exhaust adapter to the engine with three (3) fixing screw provided (M4x15 2pcs., M3.5x12 1pc.)

Instaaall the silencer as follows.

1.

2. Secure the silencer to the exhaust adapter with fixing screw (M4x18 Allen screw) using 3.0mm Allen key.

Exhaust Adapter

Model engines generate considerable heat. Do not touch any part of your engine until it has cooled. Contact with the muffler (silencer), cylinder head or exhaust header pipe, in particular, may result in a serious burn.

10

Be sure to use a pressurized fuel system by connecting the muffler pressure nipple to the vent-pipe of the fuel tank.

FUEL TANK LOCATION

•

Attention to tank height

Fuel level

10mm

For installation in the model a 500cc tank is Suggested. These will allow 10-12 minute flights.Locate the fuel tank so that the top of the tank is 5-10mm (1/4-3/8") above the level of the needle-valve.

The role of the glowplugWith a glowplug engine, ignition is initiated by the application of a 1.5-volt power source. When the battery is disconnected, the heat retained within the combustion chamber remains sufficient to keep the plug filament glowing, thereby continuing to keep the engine running. Ignition timing is 'automatic' : under reduced load, allowing higher rpm, the plug becomes hotter and, appropriately, fires the fuel/air charge earlier; conversely, at reduced rpm, the plug become cooler and ignition is retarded.

Since the glowplug and fuel combination used may have a marked effect on performance and reliability, it would be worthwhile to experiment with different plug types.Recommended O.S. plug is No8. Carefully install plug finger-tight, before final tighten-ing with the correct size plug wrench.

GLOWPLUG

11

Install a plug suitable for the engine.Use fuel containing a moderate percentage of nitromethane unless more is essential for racing events.Do not run the engine too lean and do not leave the battery connected while adjusting the needle.

However, plug life can be extended and engine performance maintained by careful use, i.e.:

Apart from when actually burned out, a plug may need to be replaced because it no longer delivers its best performance, such as when:

When to replace the glowplug

Filament surface has roughened and turned white. Filament coil has become distorted.Foreign matter has adhered to filament or plug body has corroded.Engine tends to cut out when idling.Starting qualities deteriorate.

••

•

•••

••

Glowplug lifeParticularly in the case of very high performance engines, glowplugs must be regarded as expendable items.

FUELSelect, by practical tests, the most suitable fuel from among the best quality fuels available in your country for model use. For the best performance, a fuel containing 5% to 20% nitromethane is preferable. Lubricants may be either castor-oil or a suitable synthetic oil ( or a blend of both ) provided that they are always of top quality.For consistent performance and long engine life, it is essential to use fuel containing AT LEAST 18% lubricant by volume. Some fuels containing coloring additives tend to deteriorate and may adversely affect running qualities.Once a satisfactory fuel has been selected and used for a while, it may be unwise to needlessly change the brand or type. In any engine, a change of fuel may cause carbon deposits in the combustion chamber or on the piston head to become detached and lodged elsewhere, with the risk of this causing unreliable operation for a while. If, however, the adoption of a different fuel is unavoidable, check the engine for the first few flights on the new fuel, by temporarily reverting to the running-in procedure.

12

14x6-8, 15x6-8, 16x6, 18x6Model engine fuel is poisonous. Do not allow it to come into contact with the eyes or mouth. Always store it in a clearly marked container and out of the reach of children.

Model engine fuel is also highly flam-mable. Keep it away from open flame, excessive heat, sources of sparks, or anything else which might ignite it. Do not smoke, or allow anyone else to smoke, near to it.

Reminder!

Reminder!

PROPELLERSSuggested propeller sizes are listed on page 15. The suitability of the prop depends on the size and weight of the model and type of flying. Determine the best size and type after the engine has been run in. Check the balance of the propeller before fitting it to the engine. Unbalanced propellers cause vibration and loss of power. Wooden propellers are to be preferred. Some nylon propellers are not strong enough to withstand the high power output of these engines and a thrown blade can be very dangerous.

For Scale

Never touch, or allow any object to come into contact with, the rotating propeller and do not crouch over the engine when it is running.

Reminder!

CARBURETOR CONTROLS (7D-RN)

The Needle-Valve:(at rear of engine)¡

The Mixture Control Screw:¡

The Throttle Stop Screw:For setting the position where the carburetor rotor is closed..

¡

Three adjustable controls are provided on this carburetor.

For adjusting the mixture strength when the throttle is fully open.

For adjusting the mixture strength at part-throttle and idling speeds, to obtain steady idling and smooth acceleration to mid speeds.

13

NOTE:Readjustment may be necessary, occasionally to allow for changes in fuel formulae, gear ratio or clutch engagement point.

STARTING

Check that the needle-valve is closed. (Do not overtighten.) Now open the needle-valve 1 -2 turns from the fully closed position and temporarily set the throttle in the fully open position.

21

2.

1.

3.

4.

Turn needle-valve clockwise to close (for leaner mixture)

Turn needle-valve counter-clockwise to open (for richer mixture)

Mark

Close

Open

Throttle Stop Screw

Mixture Control Screw(Mixture Control Valve)

Install an appropriate propeller and tighten securely.

To facilitate electric starting, fit an spinner for centring the rubber drive insert of the starter.

Fill the fuel tank. Do not allow fuel to overflow into the silencer, otherwise the engine may become flooded and difficult to start.

1.5~2mm

5. Open the throttle approx.

(This is to avoid unnecessarily high r.p.m. when the engine starts.)

14

6. Connect battery leads to glowplug.

Bring electric starter into contact with spinner-nut or spinner and depress starter switch for one or two seconds. Repeat if necessary.When the engine starts, withdraw the starter im-mediately.

7.

Attention : Do not choke the carburettor air intake when applying the starter. This could cause an excessive amount of fuel to be drawn into the cylinder which may initiate an hydraulic lock and damage the engine.If the engine does not start within 10 repeat applications of the starter, remove the glow-plug, check that it glows brightly and that the cylinder is not flooded with fuel. (To eject excess fuel, close needle-valve and apply starter with glowplug removed.) Then try again.

VERY IMPORTANT!Before being operated at full power (i.e. at full-throttle and with the needle-valve closed to its optimum setting) the engine must be adequately run-in, otherwise there is a danger of it becoming overheated and damaged.

RUNNING-IN ("Breaking-in")

All internal-combustion engines benefit from extra care when they are run for the first few timesknown as running-in or breaking-in. This allows the working parts to mate together under load at operating temperature. Therefore, it is vitally important to complete the break-in before allowing the engine to run continuously at high speed and before finalizing carburetor adjustments. However, because O.S. engines are produced with the aid of the finest modern precision machinery and from the best and most suitable materials, only a short and simple running-in procedure is called for and can be carried out with the engine installed in the model. The process is as follows.

Install the engine with the propeller intended for your model. Open the needle-valve to the advised starting setting and start the engine. If the engine stops when the glow plug battery disconnected, open the needle-valve to the point where the en-gine does not stop.Run the engine for one minute with the throttle fully open, but with the needle-valve adjusted for rich, slow "four-cycle"operation.

1.

15

Now close the needle-valve until the engine speeds up to "two-cycle"operation and allow it to run for about 10 seconds, then reopen the needle-valve to bring the engine back to "four-cycle"operation and run it for another 10 seconds. Repeat this procedure until the fuel tank is empty.

Re-start and adjust the needle-valve so that the engine just breaks into "two-cycle" from "four-cycle" operation, then make three or four flights, avoiding successive "nose-up" flights.

During subsequent flights, the needle-valve can be gradually closed to give more power. However, if the engine shows signs of running too lean, the next flight should be set rich. After a total of ten to fifteen flights, the engine should run continuously, on its optimum needle-valve setting, without loss of power as it warms up.

After the completion of the running-in adjust the carburetor at optimum setting referring to MIXTURE CONTROL VALVE ADJUSTMENT section and SUBSEQUENT READJUSTMENT section.

2.

3.

4.

5.

Slowly advance the throttle to its fully open position, then gradually close the needle-valve until the exhaust note begins to change. (4-cycle to 2-cycle)At this point, disconnect the battery from the glowplug, taking care that the battery leads or glowplug clip do not come into contact with the rotating propeller. If the engine stops when the battery is disconnected, close the needle-valve about 30˚ and restart.

As the needle-valve is closed slowly and gradually, the engine r.p.m. will increase and a continuous high-pitched exhaust note, only, will be heard. Close the needle-valve 10-15˚ and wait for the change of r.p.m. After the engine r.p.m. increases turn the needle-valve another 10-15˚ and wait for the next change of r.p.m. As the speed of the engine does not instantly change with needle-valve readjustment, small move-ments, with pauses between, are necessary to arrive at the optimum setting.

Optimum needle setting(1)

Optimum needle setting(2)

16

20~45°

Needle-valve adjustment diagram

This diagram is for reference purposes only. Actual needle positions may differ from those shown.

To stop the engine, close the throttle completely to cut off fuel/air supply.

Note :

•

Practical best(optimum) needle-valve setting

Exhaust note starts to change.

Disconnect battery leads from glowplug at about this point.

Clear, high-pitched two-stroke exhaust note

Maximum rpm setting("Lean").

STARTING"Rich" needle-valve setting when starting the engine.

The engine may stop if the battery leads are disconnected from the glowplug while the engine is running rich.

Enginestops

Revolu

tio

ns

sta

rtt

todecre

ase

.to

de

6

7

1

2

5

4

3

Intermittent, high-pitched two-stroke note superimposedon low "four-stroke" sound.

Note: Although this is a two-stroke engine it fires like a four-stroke at these rich needle-valve settings-i.e. ignition of the fuel charge takes place at every fourth stroke of the piston instead of at every second stroke.

17

IDLING ADJUSTMENT CHART

Start the engine.

Make sure that the throttle isfully open.

Adjust the neede-valve.

Close the throttle gradually.

Find the idling position.

Fix the idling position.

Open the throttle fully.

Does the engineregain full power?

Continue running at high speedfor 10 seconds.

Close the throttle.

Run at idling speed for 5 seconds.

Does the engine stop?

Apply full throttle.

Does the engineregain full power immediately?

OKRefer to the next section.

Re-set the idling position ata little higher r.p.m.

Set the throttle opening by means of the throttle trim onthe transmitter so that the lowestpractical speed, without risk ofthe engine stopping,is obtained.

The position where the lowestpossible r.p.m. ,with steady running, is obtained.

20-30˚ open from maximumr.p.m. setting.

Yes.

No.

Yes.

Engine stops.

Engine stops.

Disconnect the batteryleads at mid speed.

Engine stops.

18

90° 90°

MIXTURE CONTROL VALVE ADJUSTMENTWith the engine running, close the throttle and allow it to idle for about five seconds, then open the throttle fully. If, at this point, the engine is slow to pick up and produces an excess of exhaust smoke, the mixture is too rich. Correct this condition by turning the Mixture Control Screw clockwise 10-20˚. If the mixture is excessively rich, engine rpm will become unstable: opening the throttle will produce a great deal of smoke and rpm may drop suddenly or the engine may stop. This condition may also be initiated by excessively prolonged idling.If,on the other hand, the mixture is too lean, this will be indicated by a marked lack of exhaust smoke and a tendency for the engine to cut out when the throttle is opened. In this case, turn the Mixture Control Screw counter-clockwise 90˚to positively enrich the idle mixture, then turn the screw clockwise gradually until the engine regains full power cleanly when the throttle is reopened.Carry out adjustments patiently until the engine responds quickly and positively to the throttle control.

Note: Mixture Control Valve adjustments should be made in steps of 10-20˚ initially, carefully checking the effect, on throttle response, of each small adjustment.

Realignment of Mixture Control Valve

Thick Lean

19

SUBSEQUENT STARTING PROCEDUREOnce the optimum needle-valve setting has been es-tablished (see page 17, Needle-valve adjustment dia-gram) the procedure for starting may be simplified as follows.

Open the needle-valve one half-turn (180°) from the optimum setting.

Set the throttle one-quarter open from the fully closed position, energize the glowplug and apply the electric starter. When the engine starts, re-open the throttle and re-adjust the needle-valve to the optimum setting.

When re-starting the engine on the same day, provided that atmospheric conditions have not changed significantly, it may be practicable to re-start the engine on its optimum(running) setting.

Note:

1.

2.

SUBSEQUENT READJUSTMENTOnce the engine has been run-in and the controls properly set up, it should be unnecessary to alter the mixture settings; except to make minor adjustments to the Needle-Valve occasionally, to take account of variations in climatic conditions.The use of a different fuel, however, particularly one containing more, or less, nitromethane and/or a different type or proportion of lubricating oil, is likely to call for some readjustment of the Needle-Valve.Remember that, as a safety measure, it is advisable to increase the Needle-Valve opening by an extra half-turn counter-clockwise, prior to establishing a new setting. The same applies if the silencer type is changed. A different silencer may alter the exhaust pressure applied to the fuel feed and call for a revised Needle-Valve setting. The use of a different glowplug may also require compensating carburetor readjustments.

20

CARBURETOR CLEANLINESS ENGINE CARE AND MAINTENANCEAt the end of each operating session, drain out any fuel that may remain in the fuel tank.

Next, energize the glowplug and try to restart the engine to burn off any fuel that may remain inside the engine. Repeat this procedure until the engine fails to fire. Remove the glowplug and eject any re-sidue by rotating the engine with an electric starter for 4 to 5 seconds while the engine is still warm.

Finally, inject some after-run oil into the engine. Rotate the engine a few times by hand, to make sure that it is free, and then with an electric starter for 4 to 5 seconds to distribute the oil to all the working parts.

Do not inject after-run oil into the carburetor as this may cause the O-ring inside the carburettor to deteriorate.

These procedures will reduce the risk of starting difficulties and of internal corrosion after a period of storage.

The correct functioning of the carburetor depends on its small fuel orifices remaining clear. The minute particles of foreign matter that are present in any fuel, can easily partially obstruct these orifices and upset mixture strength so that engine performance becomes erratic and unreliable.O.S.'Super-Filters'(large and small ) are available, as optional extras, to deal with this problem. One of these filters, fitted to the outlet tube inside your refueling container, will prevent the entry of foreign material into the fuel tank. It is also recommended that a good in-line filter be installed between the tank and needle-valve. Do not forget to clean the filters regularly to remove dirt and lint that accumulate on the filter screen. Also, clean the carburetor itself occasionally.

Note:

1.

2.

3.

21

y

2

3

4

7

r

5

6

8

q

=

-

9

0

e

t

C.M4x10

S.M3x3

w

1

u

u-1

u-2u-3u-4

u-5

i

C.M3.5x18

--1

EXPLODED VIEW

✽ Type of screw

C…Cap Screw F…Flat Head Screw N…Round Head Screw S…Set Screw

22

Specifications are subject to alteration for improvement without notice.

ENGINEN PARTS LIST

2920400029203100292034002920320029206000290170042920500029081010290817192961010029208020292082002903100929201000460300082920202029214000290070057170424028282000282819702498183726381501267113054618195029213000716080012902500024025923290253002902540029025507

1

2

3

4

5

6

7

8

9

0

-

--1

=

q

w

e

r

t

y

u

u-1

u-2

u-3

u-4

u-5

i

No. DescriptionCode No.

Drive Hub

Connecting Rod

Woodruff Key

Crankshaft

Crankcase

Locknut Set

Piston PinPiston Pin Retainer

Cover Plate

Piston Ring

Cylinder HeadCylinder Liner

Piston

Screw SetFuel Outlet

Remote Needle Valve AssemblyNeedle

"O" Ring

Gasket Set

Set-screw

Carburettor Retainer

Ratchet Spring

855 Silencer Assembly

Crankshaft Ball Bearing(Front)

Remote Needle Valve Bracket(108FSR)

Carburettor Complete(Type 7D-RN)

Crankshaft Ball Bearing(Rear)

Clow Plug No.8

Pressure FittingAssembly ScrewRetaining ScrewExhaust Adapter

23

1

2

3

8

7

6

4

5

9

0

2-1

5-1

7-1

7-2

1

2

2-13

4

5

5-16

7

7-17-28

9

0

2688160329081305248818242908120026881311268814062688142429081110271816002718162027181610226819532288130029015019

"O" RingCarburettor Rotor

Carburettor Body

Mixture Control Valve Assembly

Throttle Stop Screw Assembly Throttle Stop ScrewThrottle Stop Screw Holder

Universal RinkThrottle Lever Assembly

Plug ScrewCarburettor Rubber Gasket

Fuel Inlet

Mixture Control Screw

Mixture Control Valve Set-screw

Specifications are subject to alteration for improvementwithout notice.

CARBURETOR EXPLODED VIEW & PARTS LIST

No. DescriptionCode No.

24

75 4642.5

30

58

60

2495

4870 121

UNF 3/8-24

17.83 cc (1.088 cu.in.)29.0mm (1.142 in.)27.0mm (1.063 in.)2,000~16,000 r.p.m.3.0 bhp / 16,000 r.p.m.750g(26.5oz.)

■■■■■■

Dimensions(mm)

Displacement Bore Stroke Practical R.P.M. Power output Weight

SPECIFICATIONS

THREE VIEW DRAWING

25

■

No.8(71608001)

A5(71605100)

■

(72403050)

■(71531000)

(71521000)

■

■

■

■

(29310110)

(72200130)

(55500004)M5

■

(71907000)

O.S. GENUINE PARTS & ACCESSORIESO.S. GLOW PLUGS

LOCK WASHER(10Sets)

SUPER FI LTER

NON-BUBBLE WEIGHT

LONG SOCKET WRENCHWITH PLUG GRIP

RADIAL MOTOR MOUNT

BOOSTER TERMINAL KIT

PROPELLER LOCKNUT SETFOR TRUTURN SPINNER

26

C Copyright 2001 by O.S.Engines Mfg. Co., Ltd. All rights reserved. Printed in Japan.

110100

TEL. (06) 6702-0225FAX. (06) 6704-2722

6-15 3-Chome Imagawa Higashisumiyoshi-ku Osaka 546-0003, Japan

URL : http://www.os-engines.co.jp

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